Gas turbines, in particular aircraft engines, are made up of a plurality of modules, for example a fan, a combustion chamber, e.g., a plurality of compressors, as well as a plurality of turbines. A plurality of stationary guide blades and a plurality of rotating rotor blades are situated in a turbine, as well as in a compressor of the gas turbine. The guide blades are arranged to be fixed with respect to a housing of the gas turbine. The rotor blades are assigned to at least one rotor and rotate with respect to the stationary guide blades and the stationary housing. If the turbine or the compressor has a plurality of stages, then guide blades and rotor blades are alternately positioned in series in the axial direction or direction of flow; several rotor blades or guide blades, which form so-called guide-blade rings or rotor-blade rings, also being arranged at an axial position, i.e., along the circumference of the rotor or the housing.
The stationary guide blades of a compressor or a turbine may be arranged to be able to move or swivel about an axis. Thus, for example, German Published Patent Application No. 39 13 102 describes a device for adjusting guide blades, where guide blades of a guide-blade ring are connected to an adjusting ring, outside of a housing of the gas turbine, via adjusting levers, so as to be able to swivel, a first end of the, or each, adjusting lever engaging with the adjusting ring, and a second end of the, or each, adjusting lever, opposite to the first end, engaging with an end of a shaft or shank of the respective guide blade. The guide blades are adjusted hydraulically, e.g., by hydraulic pistons.